When ore deposits at the surface or from shallow mines started to run out, miners needed to dig deeper underground to follow the rich, near-vertical mineral lodes that had formed millions of years ago along cracks or fissures in the rock.
It wasn’t digging deeper that proved to be the biggest problem to early miners, but finding a way to remove the water from the shafts and levels (tunnels) so they could get to the ore. Any excavations dug below the water table (the natural level below which the ground is saturated with water) quickly filled with water, creating a constant demand for pumping and drainage so that work could continue.
At first ‘water kibbles’ – buckets or leather bags – were used to pull water up from shallow mines. This involved men or horses on the surface hauling the water up the mine shaft. Sometimes the kibbles were pulled up by winding the rope around a large drum rotated by horses – known as a horse whim. This method was slow (to avoid the ropes breaking) and there was a lot of wear and tear on the kibbles as they rubbed against the rock sides of the shafts. Increased demand for minerals meant mines were sunk even deeper, requiring greater volumes of water to be removed from further underground – so a more efficient solution was needed.
Rag and chain
Rag and chain pumps were constructed from a series of interconnecting wooden pipes, made from hollowed out logs that reached all the way down to the lowest point of the mine. An endless chain (looped so it could be continuously pulled round and round) with balls of rags attached at intervals was pulled up through the pipe, drawing the water up with it in a continual flow.
New water-powered inventions were quickly adapted for use in the Cornish mining industry.
Water power was also harnessed to drain mines using European continental technology known to have been in use since the 16th century. Waterwheels on or near the surface were commonly used to wind the chain of the rag and chain pumps if water was readily available. If the mine was near a river or stream this system would be relatively easy to set up, but elsewhere, man-made watercourses – known as leats – were needed to channel the water to drive the wheels.